One of the major breakthroughs needed to convert people into cyborgs is a system that converts glucose into energy to power the implanted electronics.

This article shows that this has finally been achieved. The prototype generated an average of ~2uW inside of rats.

You really need more like 10mW inside of humans to be useful - but this prototype works enough that big companies with money will probably start investing in it. I predict 5-10 years before you'll see it commercially used in humans.